Orac's amusing April Fools post concerning the implications of chiropractic on global warming reminded me of an important way pseudoscience differs from science: it is made up of islands of knowledge rather than being a continuous whole as science is. Consider this graph Alex Palazzo provided the other day on Transcription. It shows the references in various papers by scientific discipline, and is a virtual spider web of mutual influence.
What this illustrates is how our knowledge is an interconnected whole. Discoveries in biology can have implications for chemistry, physics, or mathematics, and vice versa. At the very least they can often independently confirm each others findings. They describe overlapping areas, with varying methods of inquiry, and thus many methods of correction. When the chemists thought they had demonstrated cold fusion, they had to answer to the physicists.
One can often move so smoothly from one discipline to another that the distinction between them becomes blurred, such as that between physics and mathematics. This stands in stark contrast to what one sees in pseudoscience. Whether it is UFO abductions, reflexology, astrology, or the latest crank physics, the one common bond is the lack of much to say about any other subject. What are the implications of the ascension of Mars on chripractic? What does the latest crank physics have to say about UFO propulsion techniques? What are the implications of cranial sacral theory on the reflexology pathways? No one seems to know or care.
This problem is in part due to the common nonfalsifiable nature of pseudoscience. It is hard to discuss the implications of one's theory if that theory makes no solid predictions. It is also due to a common mindset, especially in the alternative medicines, that skepticism and critical analysis is inappropriate, like being told one has too much negative energy.
Thus, rather than an interconnected whole like science, pseudoscience tends to create islands of knowlege, confident within their sphere of immediate relevance, and with nothing to say outside that arena. The Intelligent Design Creationists refusal to even entertain a discussion of the nature of the designer is a perfect example. So it is a good idea to keep this in mind when evaluating claims of all sorts. If it seems like whatever theory is being pitched has little impact on any other area of knowledge, or worse yet is totally inconsistent with it, there is an excellent chance you are dealing with pseudoscience.